The invention relates to fluid filters, and more particularly to improved sealing of the filter media end.
The invention arose during continuing development efforts relating to filter elements having pleated filter media having a plurality of pleats in a closed loop, typically annular, for example as shown in U.S. Pat. Nos. 6,149,700, 6,261,334, 6,391,076, 6,398,832, all incorporated herein by reference. The closed loop pleated filter media has an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips, and has a hollow interior extending along a given axis. Fluid flows axially in the hollow interior, before or after flow through the media, depending on whether the flow is inside-out or outside-in. The filter element has an open axial end providing an axial flow passage therethrough along the axis communicating with the hollow interior.
The present invention relates to improved sealing of the pleat ends at the open axial end of the filter element, including improvements in both the effectiveness of the sealing and manufacturing efficiency for cost reduction. The invention further relates to other filter media end sealing techniques.